Hinged plastic box



Dec. 7, 1965 E. H. GESSNER 3,221,919

HINGED PLASTIC BOX Filed D80. 24, 1963 14 Mi 10 i 'n f \e I'II'I'I'II' INVENTOR,

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ATTORNEY5 United States Patent 3,221,919 HINGED PLASTIC BOX Edward H. Gessner, Norristown, Pa. (241 N. Main St., Ambler, Pa.) Filed Dec. 24, 1963, Ser. No. 333,070 9 Claims. (Cl. 220-31) This invention relates to improvements in hinged plastic box structures of the class in which the hingedly connected box members and their hinge straps are molded of a flexible plastic material as integral parts of a unitary box structure.

More particularly the invention relates to the provision in such box of positioning means for retaining the box lid in an open display position.

In the production of such boxes it has been customary to mold the box body and lid in relatively open or swung apart positions in which they are interconnected by hinge straps. Thereafter, following removal of a box from the mold, in order to close the lid on the box body it has been necessary to swing the lid from its initial molded position into vertically registering and closing relation with the box body.

Such boxes are often used for jewelry and small articles in connection with the sale of which it is desirable to maintain the box lid opened to approximately a vertical position to permit inspection of the box contents by potential purchasers.

Boxes of the class here involved have been somewhat unsatisfactory for such displays due to the tendency of the plastic hinge strap either to return the box lid to the position in which it was originally molded, or in response to increase in ambient temperature to permit closing movement of the lid.

It is accordingly a primary object of the invention to provide such a box with positioning means formed integrally with the rest of the box structure as a homogeneous portion thereof for limiting the opening movement of the lid beyond a desired display position.

It is a further object to provide such a positioning means which is capable of retaining the lid in a predetermined open display position in which further opening movement is positively resisted and closing movement is yieldably resisted.

It is a still further object to provide such a positioning means which will permit movement of the box lid and the body member from their initially molded open positions to positions in vertically registering closed relation without damage to said positioning means or other portions of the box structure, and which thereafter will positively rea sist the opening of the lid beyond a predetermined angular position with respect to the box body.

Also it is an object to provide such a positioning means in which one of the stop faces or surfaces is that of a freeended lug or projecting portion of the stop element arranged to yield and flex rearwardly responsive to the exertion of an excessive amount of opening force and the lid, and in so flexing to yield about a fold line which thereafter acts as a permanent hinge yieldably connecting the lug to the stop, with the lug projecting into the path of movement of the detent on the lid to thereafter serve as a yielding abutment for yielding engagement with the detent.

In order to achieve the foregoing objects, the positioning means of the invention comprises a stop element molded as an integral portion of the box structure and carried by one of the box members, said stop element having a free end projecting across the axis defined by the hinges or hinge straps interconnecting said members and into the path of angular movement about said axis of a detent carried by the other member and projecting radially toward such axis. At least one of these elements is sufficiently resiliently flexible and yieldable, and the elements are relatively so shaped, as to freely deflect and override each other without damage as the members are initially moved angularly from their original molded positions into closed relationship.

To positively resist subsequent opening of the box lid beyond the desired display position, the stop element is provided with an abutment or stop face extending generally transversely across the path of angular opening movement of the lid for abutting engagement with the said detent, the detent presenting a similarly disposed cooperating face or surface.

For retaining the lid in its predetermined display position as above mentioned, the stop element may be formed with a notch adapted for reception of said detent with one sidewall of the notch defining the stop face for positively resisting further opening movement of the lid, the other sidewall of the notch being disposed and proportioned to yieldably resist closing movement of the lid by engagement with said detent.

The foregoing as well as other incidental objects and advantages are attained by the structure illustrated by way of example only in the accompanying drawings, in which:

FIGURE 1 is a perspective view of a box to which the invention is applied;

FIGURE 2 is a fragmentary plan view of the hinged end of the box;

FIGURE 3 is a vertical section on the line 3-3 of FIGURE 2, in which the lid is shown in full lines in its display position, and is shown in broken lines, both in its fully opened position as when initially taken from the mold, and in its closed position; and

FIGURE 4 is an enlarged fragmentary view of the interconnected hinged portions of the box body and lid, showing the lid in full lines in its display position and in broken lines in its closed position.

Referring now in detail to the accompanying drawings, the invention is shown as applied to a generally conventional molded plastic box structure comprising a box body member 10 and cooperating box cover or lid member 12 connected to the body member by hinges in the form of the plastic hinge straps generally designated 14. All of said parts as well as the further parts hereinafter described are integrally interconnected to form a unitary structure adapted to be molded of a suitable resiliently flexible plastic material, for which purpose a polypropylene plastic has been found admirably adapted due to its resistance to fatigue under flexing.

The body member 10 of the box may be of a conventional configuration including a rectangular flat bottom 16 surrounded by marginal upstanding sidewalls 1818 and end walls 20 and 22 respectively. These walls are interconnected and formed to provide a continuous upwardly presented shoulder 24, at the inner periphery of which is preferably located a continuous upwardly projecting positioning flange 26 for reception within the cover or lid 12 in usual manner as same is seated upon the shoulder 24 to close the box.

The lid or cover 12 of the structure is of generally similar configuration to the body 10, including a generally horizontal panel 28 surrounded by the generally vertical continuous marginal wall structure 30, having a coplanar upper edge or lip 32 adapted to encircle the upstanding flange 26 and to seat upon the abutting surface 24 of the box body in the closed condition of the box. In the drawings the box body is shown as provided with integral snap catch means exemplified by the upwardly projecting catch or hook 34 formed integrally with the end 22 of the box body for cooperation with the inwardly projecting lip 3 or tab 36 carried adjacent the lower edge of the corresponding wall portion of the cover or lid.

In order to best adapt the hinges 1414 for use with the present invention there are two such relatively spaced hinges or hinge straps 14, each integrally connected at its opposite ends to the respective box members and 12. These hinges define a common axis 38 of relative angular movement between the box members 10 and 12 in the plane of the relatively abutting upper wall edges or shoulders 24 and 32 of the respective members. The axis 38 is located midway between said members in the position in which they are initially formed or molded, wherein said members and hinges are relatively aligned with each other in a common plane. The two relatively foldable halves or portions of each hinge member 14 are integrally connected to each other along a fold line 38 which defines the axis above mentioned. It Will be seen that each section of each hing 14 is of maximum thickness at its juncture with its associated box member, and then progressively decreases to a minimum thickness at the fold line 38 in accordance with known practice.

It has been common practice to form such a box structure by molding same as a unitary device in which the parts are formed or molded with the lid 12 opened. For instance it may be opened fully to a position at 180 to and in a common plane with the body 10, such position of the lid being indicated at M in FIGURE 3, though it may, as initially molded, be in other angular positions with relation to the box body, as will be apparent.

The improvement of the present invention consists in the combining with such a box structure of positioning elements 40 and 42 which are also formed or molded of the same material as and constitute integral portions of the unitary box structure.

For the purpose of insuring accurate coaction between these elements incident to their relative angular movement about the axis 38, it is desirable, though not essential, to locate them in the space between the two hinges 14-14, as in the illustrated embodiment. However, such elements will normally cooperate satisfactorily so long as they are located in reasonable proximity to the hinge structure which defines their axis of relative angular movement.

The positioning element 40 which is sometimes hereinafter referred to as the stop element, is in the form of a free ended tab or finger having its base integrally affixed to the box body member 10 medially of the end wall thereof. This stop element or finger 40 projects across the axis 38 so that its free end is directed radially away from the axis on the opposite side of said axis from the box body 10, and is located in the path of angular movement .of the cooperating positioning element 42, sometimes herein referred to as the detent element.

Detent element 42 is formed at a suitable location on the box cover or lid 12 as a radial inward projection having its free end or edge directed toward the axis 38. Obviously the relative positions of the free ends of the said elements 40 and 42 will be so chosen as to cause their inter-engagement at the point where it is desired to arrest the opening swinging movement of the lid 12. Normally this will be such that the inter-engagement will occur after the lid 12 has swung open through approximately 90 or slightly more, at which time the end edge of detent 42 will abut against the free end of stop 40. As is shown best in FIGURE 4, the free end face of the stop 40 is formed with a radially opening retainer notch 44 for holding reception of the radially inner extremity of the detent 42, one face or sidewall 46 of the notch being presented generally radially to the axis 38 and thus transversely to the opening angular movement of the lid, whereby to positively resist same. The other sidewall 48 of the notch is preferably of somewhat lesser height than the sidewall 46 so that the sidewall 48 will but yieldingly resist and avoid damage resulting from the return or closing movement of the lid as contrasted to the more positive action of the sidewall or abutment 46 which preferably offers positive resistance to swinging of the lid. Obviously, however, the height and the angular disposition of the sidewall 48 relative to the path of angular movement of the detent element 42 may be varied as desired to achieve either a positive or a yielding opposition to such movement.

The finger or tab which defines the stop preferably is tapered outwardly toward its free end and is of sufliciently small cross-section as to be stiflly flexible or yieldable in a direction transverse to its length. It will be noted that the stop 40 in the preferred embodiment has or includes a reinforcing web 49 extending upwardly from its base but terminating at or below the level of the axis 38 and the shoulder 24 on which the lid seats, thus to avoid interference with the detent 42 when the lid 12 is closed on the box body 10. The detent element 42 may be formed of sufficiently thin cross-section to permit slight flexing about its connection to the lid as said elements override each other.

In the operation of the invention, after the box is first formed and taken from the mold, the box members 10 and 12 will lie in the same plane and will be relatively spaced apart equidistantly on opposite sides of the axis 38 defined by their connecting hinge straps 14-14. The position of the lid at this time is indicated by the broken line showing M in FIGURE 3. In order to assemble the lid 12 onto the box body 10, the lid 12 is swung through an angle of 180 around the axis 38 to the position illustrated by the broken line showing C in FIGURES 3 and 4. During this movement, the detent 42 will engage and ride over the free end of the stop 40 with resulting resilient radial deflection of one or both members or elements 40 and 42 in such manner that they pass over each other without damage to either.

At the end of this angular movement, the lid 12 will have been seated upon the box body 10 with the flange 26 received within the lid walls 30, and the lip or flange 36 of the lid will have snapped into operative position beneath the catch 34 carried by the body, to thus retain the parts in their closed relationship all as indicated in the broken line position C of the lid in FIGURE 3. Release of the catch 34 when it is desired to open the box, may be caused in usual manner simply by pressing inwardly on the end wall 22 to deflect the catch 34 inwardly and disengage it from the flange 36, whereupon a certain amount of opening movement will normally be automatically produced due to the elasticity of the hinges 14.

Where it is desired to hold the lid open to approximately in a display position, such as is shown in full lines in FIGURE 3, the lid will be swung open until the detent 42 is received in notch 44 with one radially presented face abutting against the generally radially presented sidewall or face 46, following which the tendency of the hinges 14 to resume their initial rectilinear configuration will normally maintain such engagement. Obviously the disposition of the abutting face 46 of the stop will firmly oppose any tendency of the hinges 14 to urge the lid 12 further toward its fully opened or aligned position with the body 10. At the same time the face or sidewall 48 of the notch will yieldingly oppose movement of the lid toward closed position.

In the event however that an excessive opening force is exerted on the top or lid 12 to move it and its detent element 42 beyond the stop face 46, this will result in a yielding of the stud or projection 45 on which the face 46 is formed. In such event the stud will yield and be folded rearwardly as shown in broken lines in FIGURE 4 while nevertheless remaining integrally connected to the stop element 40 along a fold line 47 which will be created at the time incident to such yielding movement and which will thereafter constitute a permanent resilient hinge connection between the stud 45 and stop element 40. This is due to the peculiar qualities of the resiliently flexible plastic material, such a polypropylene plastic from which the box structure in its entirety is formed. After the initial creation of such a fold line or hinge 47, the stud 45 will still be operative to function as a yieldable means for resisting opening of the lid therepast and will of course permit movement of the lid therepast to closed position.

In this application I have shown and described only the preferred embodiment of the invention. However, I recognize that the invention is capable of still further embodiments and that its various details may be modified in obvious ways, all without departing from the invention as defined in the appended claims.

Having thus described my invention, I claim:

1. A hinged box structure having all of its hereinafter stated parts integrally interconnected and forming homogeneous portions or" a unitary structure of resiliently flexible material, comprising a box body member, a box cover member, hinge means interconnecting said members for relative swinging movement into and from a closed position about an axis spaced equidistantly from the respective members and outside of said box structure, positioning elements fixedly carried by the respective members, one of said elements being positioned wholly on one side or" said axis, and having a free end projecting toward but spaced from said axis to move in an arc therearound incident to relative swinging of said box members, the other said element projecting across the said axis and having a free end positioned to intersect the arcuate path of movement described by the free end of said one element at a suitable point in the relative swinging movement of said members, one of said elements being resiliently radially yieldable relative to said axis and of a length to permit free ends of said elements to override each other without damage incident to the exertion of a sufficient swingin; "'ce on said members.

2. A hinged structure as defined in claim 1 in which one of sa :ments is formed with a radially opening retainer HOILJ in its free end for holding reception of the radial extremity of the other said element to yieldably maintain the said box members in a predetermined position of relative angular adjustment about said axis.

3. The combination of claim 2 in which the said detent element is formed of sufliciently thin cross-section to permit flexing and radial outward displacement of its inner edge as said elements override each other.

4. A hinged box structure comprising a box body member and a box closure member, hinge means interconnecting said members for relative swinging movement through 180 into and from a closed registering position about an axis spaced equidistantly from the respective members, a detent element aflixed to one of said members and having a free inwardly projecting end directed radially toward and spaced from said axis, and a stop element affixed to the other said member, said stop element having a free end on the remote side of said axis from said member to which it is aflixed, said free end of the stop element being directed away from said axis and positioned in the arcuate path described by said detent element incident to relative swinging movement of said members, one of said free ends being formed with a retainer notch for reception of said free end, one of said elements having a resiliently radially yieldable free end portion for deflection away from said arcuate path incident to the exertion of a suflicien-t swinging force on said members.

5. A hinged box structure comprising a box body member and a closure member, relatively spaced hinges interconnecting said members for swinging movement through substantially into and from registry with each other in the closed position of the structure and about an axis equidistantly spaced from the respective members, the combination with said box structure of a detent element affixed to one said member between said hinges and projecting radially therefrom with a free end directed inwardly toward said axis but spaced radially from said axis, and a stop element aifixed to the other said member between said hinges, said stop element having a free end portion projecting into the arcuate path of movement of said free end portion of the detent element to arrest the arcuate movement of said stop element and its associated box member, said free end of the stop element being resiliently yieldable to a nonobstructing position to permit movement of the detent element therepast as the members are swung toward relatively closed position, said box members, hinges, detent and stop elements all being integral parts of a unitary structure of stifliy resilient plastic material.

6. A hinged box structure of the class in which all portions of said structure, including a box body member and a box cover member, hinges interconnecting said members, and the parts hereinafter enumerated are initially molded as an integral unitary structure of homogeneous resiliently flexible material throughout, with the body and cover members initially in relatively open spaced relation and integrally interconnected by said hinges, said hinges defining an axis midway between said members about which said members may be swung to a relatively closed and vertically registering position, a. detent element affixed to said cover element and projecting radially toward said axis, and a stop element aflixed to said body member and projecting across said axis, said stop element having a free end directed away from said axis and located in the path of swinging movement of said detent element, said stop element being formed of stiflly resiliently flexible material adapted for deflection of its free end out of the path of said detent element to permit forcing therepast of the detent element.

7. A hinged box structure as defined in claim 6 in which said stop element and said detent element are provided at their free ends with circumferentially opposed faces extending predominately radially to said axis for abutting engagement to positively limit the relative opening movement of said members.

8. A hinged box structure as defined in claim 7 in which said stop element is formed with a notch in its free end opening away from said axis for latcln'ng reception of the free end of said detent element.

9. A hinged box structure as defined in claim 6 in which said stop element is formed with a hinged lug at its free end projecting normally into the path of movement of said detent element to yieldingly resist opening movement of the lid.

References Cited by the Examiner UNITED STATES PATENTS 2,527,318 10/1950 Magnus 220-3 1 2,687,157 8/1954 Cowan 22031 3,120,879 8/ 1964 Warner 220-31 THERON E. CONDON, Primary Examiner. 

1. A HINGED BOX STRUCTURE HAVING ALL OF ITS HEREINAFTER STATED PARTS INTEGRALLY INTERCONNECTED AND FORMING HOMOGENEOUS PORTIONS OF A UNITARY STRUCTURE OF RESILIENTLY FLEXIBLE MATERIAL, COMPRISING A BOX BODY MEMBER, A BOX COVER MEMBER, HINGE MEANS INTERCONNECTING SAID MEMBERS FOR RELATIVE SWINGING MOVEMENT INTO AND FROM A CLOSED POSITION ABOUT AN AXIS SPACED EQUIDISTANTLY FROM THE RESPECTIVE MEMBERS AND OUTSIDE OF SAID BOX STRUCTURE, POSITIONING ELEMENTS FIXEDLY CARRIED BY THE RESPECTIVE MEMBERS, ONE OF SAID ELEMENTS BEING POSITIONED WHOLLY ON ONE SIDE OF SAID AXIS, AND HAVING A FREE END PROJECTING TOWARD BUT SPACED FROM SAID AXIS TO MOVE IN AN ARC THEREAROUND INCIDENT TO RELATIVE SWINGING OF SAID BOX MEMBERS, THE OTHER SAID ELEMENT PROJECTING ACROSS THE SAID AXIS AND HAVING A FREE END POSITIONED TO INTERSECT THE ARCUATE PATH OF MOVEMENT DESCRIBED BY THE FREE END OF SAID ONE ELEMENT AT A SUITABLE POINT IN THE RELATIVE SWINGING MOVEMENT OF SAID MEMBERS, ONE OF SAID ELEMENTS BEING RESILIENTLY RADIALLY YIELDABLE RELATIVE TO SAID AXIS AND OF A LENGTH TO PERMIT FREE ENDS OF SAID ELEMENTS TO OVERRIDE EACH OTHER WITHOUT DAMAGE INCIDENT TO THE EXERTION OF A SUFFICIENT SWINGING FORCE ON SAID MEMBERS. 